FlakM

Setting up qemu VM using nix flakes

Did you know that it is rather easy to setup a VM to test your NixOs configuration?

Create simple flake:

# flake.nix
{
  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";

toraritte

Yes, there are several ways to do this, but none of them are as direct and simple as git v2.1.2; htop v1.2.3 and come with a lot of caveats.

aside
Specifying versions for programming language packages are possible too, but that topic seems to be even messier. The most promising standardization effort to date is [dream2nix][1].

0. Methods

That is, available at the time of this writing:

0.1 "versioned" attribute paths (if available)

moyix

The ffast and the Furious

This is a small and admittedly contrived demo showing how some weird but safe code could become vulnerable if run in an environment where some shared library has changed the FPU's FTZ/DAZ bits to force denormals to zero.

To run it:

# Create an empty file
$ touch gofast.c      

emidoots

Because cross-compiling binaries for Windows is easier than building natively

I want Microsoft to do better, want Windows to be a decent development platform-and yet, I constantly see Microsoft playing the open source game: advertising how open-source and developer friendly they are - only to crush developers under the heel of the corporate behemoth's boot.

The people who work at Microsoft are amazing, kind, talented individuals. This is aimed at the company's leadership, who I feel has on many occassions crushed myself and other developers under. It's a plea for help.

The source of truth for the 'open source' C#, C++, Rust, and other Windows SDKs is proprietary

You probably haven't heard of it before, but if you've ever used win32 API bindings in C#, C++, Rust, or other languages, odds are they were generated from a repository called microsoft/win32metadata.

jix

// This is a technique to emulate lifetime GATs (generic associated types) on stable rust starting
// with rustc 1.33.
//
// I haven't seen this exact technique before, but I would be surprised if no one else came up with
// it. I think this avoids most downsides of other lifetime GAT workarounds I've seen.
//
// In particular, neither implementing nor using traits with emulated lifetime GATs requires adding
// any helper items. Only defining the trait requires a single helper trait (+ a single helper impl
// for the 2nd variant) per GAT. This also makes the technique viable without any boilerplate
// reducing macros.

est31

Postfix macros in Rust

The problem

Rust has many postfix combinators, for example the .unwrap_or(x) and .unwrap_or_else(|| x) functions. They are useful if you want to extract some value from an optionally present value, or if not, provide an alternative value. It's really nice and tidy to read:

StarArawn

// In bevy there are the following macros/derive traits:
// RenderResources, RenderResource, render_resources
// These allow you to link data from bevy to your shader directly.
//
// Struct data is linked to the shader via a naming convention.
//
// render_resources allows you to specify some specifics:
// from_self - Specifies that the following struct is a single binding.
// buffer - Specifies the following field is a uniform Buffer
// ignore - Ignores the following field and wont be sent to the GPU

woctezuma

Get pretrained weights:

wget https://dl.fbaipublicfiles.com/detr/detr-r50-e632da11.pth

Remove class weights

checkpoint = torch.load("detr-r50-e632da11.pth", map_location='cpu')
del checkpoint["model"]["class_embed.weight"]
del checkpoint["model"]["class_embed.bias"]
torch.save(checkpoint,"detr-r50_no-class-head.pth")

xarinatan

How to set up PulseAudio over Network

PulseAudio actually has great networking capabilities. Especially when combined with Avahi/Zeroconf it is especially easy to set up, though technically it should also be possible without.

Setting up the server

• Open /etc/pulseaudio/default.pa
• At the end of the file, add load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1;192.168.254.0/24 auth-anonymous=1 to activate networked audio from 192.168.254.0-255 without needing authentication.
• Kill pulseaudio, it should be auto-restarted, or restart your login session to activate the changes. You should now be able to set PULSE_SERVER=192.168.254.XXX and have the remote audio working! If not check the firewall settings, PulseAudio seems to open a random port by default.

Setting up automatic configuration and discovery

• On both the server and client, install pulseaudio-module-zeroconf and avahi, then after installing make sure Avahi always runs by running systemctl enable --now avahi-daemon

moorepants